/* ==========================================================================
   /styles/evolution.css
   The Evolution — kaskade.systems
   Doctrine, not deck. Amber on navy. Fraunces + IBM Plex Mono.
   No glassmorphism. No gradients. No vapor.
   ========================================================================== */


/* ----- fonts (self-hosted; drop into /fonts/) ----------------------------- */

@font-face {
  font-family: 'Fraunces';
  src: url('/fonts/Fraunces.woff2') format('woff2-variations'),
       url('/fonts/Fraunces.woff2') format('woff2');
  font-weight: 100 900;
  font-style: normal;
  font-display: block;
}

@font-face {
  font-family: 'IBM Plex Mono';
  src: url('/fonts/IBMPlexMono-Regular.woff2') format('woff2');
  font-weight: 400;
  font-style: normal;
  font-display: block;
}

@font-face {
  font-family: 'IBM Plex Mono';
  src: url('/fonts/IBMPlexMono-Medium.woff2') format('woff2');
  font-weight: 500;
  font-style: normal;
  font-display: block;
}


/* ----- root tokens ------------------------------------------------------- */

:root {
  --navy:           #020617;
  --amber:          #fbbf24;
  --amber-soft:     #fef3c7;
  --cyan:           #67e8f9;
  --bone:           #f8fafc;
  --bone-dim:       rgba(248, 250, 252, 0.72);
  --bone-faint:     rgba(248, 250, 252, 0.35);

  --border:         rgba(255, 255, 255, 0.08);
  --border-2:       rgba(255, 255, 255, 0.14);
  --border-amber:   rgba(251, 191, 36, 0.28);
  --border-cyan:    rgba(103, 232, 249, 0.22);

  --hairline:       rgba(248, 250, 252, 0.1);
  --hairline-amber: rgba(251, 191, 36, 0.28);

  --serif: 'Fraunces', Georgia, 'Times New Roman', serif;
  --mono:  'IBM Plex Mono', 'SFMono-Regular', Menlo, Consolas, monospace;

  --max-width: 720px;
  --gutter:    2rem;
}


/* ----- reset ------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-behavior: smooth;
}

body {
  background: var(--navy);
  color: var(--bone);
  font-family: var(--serif);
  font-variation-settings: "SOFT" 50, "opsz" 14, "wght" 400;
  line-height: 1.6;
  min-height: 100vh;
  padding: 6rem var(--gutter) 6rem; /* top padding clears fixed nav */
  overflow-x: hidden;
}

/* subtle ambient atmosphere to match main site */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 50% 40% at 20% 10%, rgba(103, 232, 249, 0.06), transparent 65%),
    radial-gradient(ellipse 40% 30% at 80% 20%, rgba(251, 191, 36, 0.04), transparent 65%),
    linear-gradient(to bottom, #0b1120 0%, #020617 60%, #01040d 100%);
  pointer-events: none;
  z-index: 0;
}

::selection { background: var(--amber); color: var(--navy); }

a { color: var(--amber); text-decoration: none; }

code {
  font-family: var(--mono);
  font-size: 0.92em;
  color: var(--amber);
  background: rgba(251, 191, 36, 0.06);
  padding: 0.08em 0.4em;
  border: 1px solid var(--hairline-amber);
  border-radius: 1px;
}


/* ----- NAV (exact match to main site) ------------------------------------ */

nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.75rem 2.5rem;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  background: rgba(2, 6, 23, 0.65);
  border-bottom: 0.5px solid var(--border);
}

.wordmark {
  font-family: var(--mono);
  font-weight: 500;
  font-size: 0.95rem;
  letter-spacing: 0.5em;
  color: var(--bone);
  text-transform: uppercase;
  text-decoration: none;
  padding-left: 0.5em;
  display: inline-flex;
  align-items: center;
}

.wordmark::before {
  content: '';
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  margin-right: 0.9em;
  animation: pulse 2.4s ease-in-out infinite;
  box-shadow: 0 0 12px var(--cyan);
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50%       { opacity: 0.4; transform: scale(1.2); }
}

.nav-menu {
  display: flex;
  gap: 2.5rem;
  list-style: none;
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
}

.nav-menu a {
  color: var(--bone-dim);
  text-decoration: none;
  transition: color 0.3s ease;
  position: relative;
}

.nav-menu a:hover,
.nav-menu a.nav-active {
  color: var(--amber);
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: -6px; left: 0;
  width: 0; height: 0.5px;
  background: var(--amber);
  transition: width 0.3s ease;
}

.nav-menu a:hover::after,
.nav-menu a.nav-active::after {
  width: 100%;
}

@media (max-width: 900px) {
  nav { padding: 1.25rem 1.5rem; }
  .nav-menu { display: none; }
}


/* ----- frame ------------------------------------------------------------- */

.frame {
  max-width: var(--max-width);
  margin: 0 auto;
  position: relative;
  z-index: 1;
}


/* ----- section title (spine page) ---------------------------------------- */

.section-title { margin-bottom: 4rem; }

.section-title .label,
.loop-header .label {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
  display: block;
  margin-bottom: 1.25rem;
}

.section-title h1 {
  font-family: var(--serif);
  font-variation-settings: "SOFT" 100, "WONK" 0, "opsz" 144, "wght" 350;
  font-size: clamp(3rem, 8vw, 5.5rem);
  line-height: 0.98;
  letter-spacing: -0.025em;
  margin-bottom: 1.75rem;
}

.section-title .subtitle {
  font-size: 1.125rem;
  color: var(--bone-dim);
  max-width: 38em;
  font-style: italic;
  line-height: 1.55;
}


/* ----- spine ------------------------------------------------------------- */

.spine { list-style: none; }

.spine-entry {
  padding: 2.25rem 0;
  border-top: 1px solid var(--hairline);
  display: grid;
  grid-template-columns: 4rem 1fr;
  gap: 1.5rem;
  align-items: start;
}

.spine-entry:last-child { border-bottom: 1px solid var(--hairline); }

.spine-entry .step-num {
  font-family: var(--mono);
  font-size: 0.7rem;
  color: var(--bone-faint);
  letter-spacing: 0.12em;
  padding-top: 0.55rem;
}

.spine-entry .meta {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bone-dim);
  margin-bottom: 0.75rem;
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
  align-items: center;
}

.spine-entry .type-tag {
  color: var(--amber);
  border: 1px solid var(--hairline-amber);
  padding: 0.2rem 0.55rem 0.18rem;
  font-size: 0.6rem;
  letter-spacing: 0.18em;
}

.spine-entry h2 {
  font-family: var(--serif);
  font-variation-settings: "SOFT" 75, "opsz" 36, "wght" 400;
  font-size: 1.65rem;
  line-height: 1.18;
  letter-spacing: -0.012em;
  margin-bottom: 0.6rem;
}

.spine-entry h2 a {
  color: var(--bone);
  border-bottom: 1px solid transparent;
  transition: color 0.18s ease, border-color 0.18s ease;
}

.spine-entry h2 a:hover {
  color: var(--amber);
  border-bottom-color: var(--hairline-amber);
}

.spine-entry .summary {
  color: var(--bone-dim);
  font-style: italic;
  font-size: 1rem;
  line-height: 1.5;
}


/* ----- loop header ------------------------------------------------------- */

.loop-header { margin-bottom: 4rem; }

.loop-header h1 {
  font-family: var(--serif);
  font-variation-settings: "SOFT" 100, "opsz" 96, "wght" 350;
  font-size: clamp(2.5rem, 6vw, 4rem);
  line-height: 1.05;
  letter-spacing: -0.022em;
  margin-bottom: 1.75rem;
}

.loop-header .meta {
  font-family: var(--mono);
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bone-dim);
  display: flex;
  gap: 2rem;
  flex-wrap: wrap;
}

.loop-header .meta .models { color: var(--amber); }


/* ----- loop sections (desire / friction / scar / carry-forward) --------- */

.loop-section { margin-bottom: 3.5rem; }

.loop-section .stage {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}

.loop-section .stage::before {
  content: '';
  display: inline-block;
  width: 1.5rem;
  height: 1px;
  background: var(--amber);
}

.loop-section p {
  font-size: 1.0625rem;
  line-height: 1.65;
  margin-bottom: 1rem;
  color: var(--bone);
}

.loop-section p:last-child { margin-bottom: 0; }

.loop-section ul { list-style: none; margin-top: 0.5rem; }

.loop-section ul li {
  padding: 0.4rem 0 0.4rem 1.5rem;
  position: relative;
  font-size: 1.0625rem;
  line-height: 1.55;
}

.loop-section ul li::before {
  content: '—';
  position: absolute;
  left: 0;
  color: var(--amber);
}


/* ----- the five-gate ----------------------------------------------------- */

.gate {
  border: 1px solid var(--hairline-amber);
  padding: 2.5rem 2.25rem;
  margin: 4rem 0;
  position: relative;
}

.gate .corner {
  position: absolute;
  width: 10px; height: 10px;
  border-color: var(--amber);
  border-style: solid;
  border-width: 0;
}

.gate .corner.tl { top: -1px;    left: -1px;  border-top-width: 1px; border-left-width: 1px; }
.gate .corner.tr { top: -1px;    right: -1px; border-top-width: 1px; border-right-width: 1px; }
.gate .corner.bl { bottom: -1px; left: -1px;  border-bottom-width: 1px; border-left-width: 1px; }
.gate .corner.br { bottom: -1px; right: -1px; border-bottom-width: 1px; border-right-width: 1px; }

.gate-title {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 1.75rem;
  text-align: center;
}

.gate-fields { list-style: none; }

.gate-field {
  display: grid;
  grid-template-columns: 7.5rem 1fr;
  gap: 1.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--hairline);
  align-items: baseline;
}

.gate-field:first-child { border-top: none; padding-top: 0; }

.gate-field .key {
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--bone-dim);
}

.gate-field .value {
  font-size: 1rem;
  line-height: 1.55;
  color: var(--bone);
}


/* ----- membrane note ----------------------------------------------------- */

.membrane {
  margin-top: 4rem;
  padding-top: 2rem;
  border-top: 1px dashed var(--hairline-amber);
}

.membrane .label {
  font-family: var(--mono);
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 1.25rem;
  display: block;
}

.membrane p {
  color: var(--bone-dim);
  font-size: 0.95rem;
  line-height: 1.6;
  font-style: italic;
  margin-bottom: 0.85rem;
}

.membrane p:last-child { margin-bottom: 0; }

.membrane ul { list-style: none; margin-top: 0.5rem; }

.membrane ul li {
  padding: 0.3rem 0 0.3rem 1.25rem;
  position: relative;
  font-size: 0.95rem;
  line-height: 1.55;
  color: var(--bone-dim);
  font-style: italic;
}

.membrane ul li::before {
  content: '·';
  position: absolute;
  left: 0;
  color: var(--amber);
  font-style: normal;
}


/* ----- page footer ------------------------------------------------------- */

.page-footer {
  margin-top: 6rem;
  padding-top: 2rem;
  border-top: 1px solid var(--hairline);
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--bone-faint);
}

.page-footer a {
  color: var(--bone-faint);
  border-bottom: 1px solid transparent;
}

.page-footer a:hover {
  color: var(--amber);
  border-bottom-color: var(--hairline-amber);
}


/* ----- responsive -------------------------------------------------------- */

@media (max-width: 600px) {
  body { padding: 5rem 1.25rem 4rem; }
  .section-title { margin-bottom: 2.5rem; }
  .spine-entry {
    grid-template-columns: 1fr;
    gap: 0.4rem;
    padding: 1.75rem 0;
  }
  .spine-entry .step-num { padding-top: 0; }
  .gate { padding: 2rem 1.25rem; }
  .gate-field { grid-template-columns: 1fr; gap: 0.4rem; }
  .loop-header .meta { gap: 1rem; }
}